1. Technical Field
The present invention generally relates to conformal coating of objects. More particularly, the present invention relates to a method and system for conformally coating objects, such as circuit boards.
2. Background Information
Conformal coating, such as, for example, acrylic, urethane or silicone, is used to, for example, protect the components on a circuit board from moisture, chemicals, dust, and shock. Conformal coating on circuit boards also acts as an insulator for electricity and heat. Because of this insulating property, some areas of a circuit board usually cannot be conformally coated, in order to preserve the electrical and/or heat conduction. Thus, conformal coating for circuit boards is performed selectively.
To accomplish selective conformal coating, requiring very precise applications, robotic dispensing systems have been employed. Such systems heretofore have provided relatively precise dispensing of conformal coating on small circuit board components, as well as the ability to spray conformal coating across larger areas of a circuit board.
However, existing robotic conformal coating systems employ a single valve. The use of a single valve is limiting in a number of ways. For example, a single type of head cannot generally provide multiple spray options tailored to the object or portion of the object that needs to be coated, e.g., wide spray versus thin stream. As another example, a single valve restricts the timing efficiency of the system.
Thus, a need exists for an improved way to apply conformal coating.